The number of people, who died in traffic accidents or were severely injured, is decreasing since years, according to official national statistics. However, the group of severely injured people is very heterogenous and covers all people who have to stay in hospital for at least 24 hours. The present investigation uses data from the DGU (Deutschen Gesellschaft für Unfallchirurgie) Trauma Registry in order to answer the question whether the number of very severely injured patients is decreasing as well. In this context, "very severely injured" patients were defined as those with an ISS (Injury Severity Score) of at least 9 points, who additionally required intensive care in hospital. A 10-year-period from 1997 until 2006 was considered, divided in two consecutive phases of 5 years each. In the second phase data could be analyzed for bicycle riders and motor bike drivers separately, due to a change in documentation. The first analysis addressed the question of a relative change in the number of very severely injured patients over time. For this, data from more than 11000 traffic accident victims from 67 different hospitals were used. For each hospital, the expected number of traffic accident victims per year was calculated as annual average. This number was compared with the actual observed annual numbers. As main result there were only minor variations of about -±10% deviation from the expected number, without an obvious trend over time. The second analyses considered the fact that a decreasing number of non-survivors in hospital could increase the number of very severely injured survivors. Annual mortality figures were compared with an expected number of deaths, based on a prognostic scoring system (RISC). This score was developed and validated in the DGU Trauma Registry. It was found that observed mortality was significantly lower in the most recent two years, and mortality rate was up to 5% lower than expected (in 2006: prognosis: 18% versus observed 13%). This effect is assumed to contribute to the fact that the number of very severely injured patients did not change. The final question was about the pattern of injuries for different types of traffic participation (car/lorry, motorbike, bicycle, pedestrian), and if there were changes over time during the last 10 years. It could be shown that drivers of cars and lorries are less frequently seen in that severely injured population , their portion reduced from 60% to 50%. Regarding the injured body region, there was a decreasing trend for head injury, in total from 69% to 60% of all patients. This decrease was observed in all subgroups of traffic participation. The only body region that showed a substantial increase was the spine, but this could also, at least in part, be induced by an improved diagnostic process with whole body CTs. Injury pattern vary substantially with respect to the type of traffic participation. Head injuries were most frequently observed in pedestrians and bicyclists (more than 70%), while motor bike drivers showed the lowest rate (45%). Car/lorry driver and motorbike riders showed the highest rates for thoracic and abdominal injuries, which could be explained by the high energy usually involved in these kind of accidents. In summary, data from the DGU Trauma Registry could well be used to describe typical injury pattern, and to evaluate relative changes over time, both in pattern and incidence rates of severely injured patients. Observation periods of 10 years or more, as in the present analysis, are appropriate to detect actual trends over time. Epidemiologic results as provided by the official federal statistics department are not possible since the registry is based on voluntary participation only.